The invention relates to vacuum bottles in general, and more particularly to improvements in bottles of the type disclosed in commonly owned U.S. Pat. Nos. 4,161,257 and 4,220,251 to Hauri and in published European patent application No. 0 288 679. Such bottles can be used for evacuation of pus or other body fluids from wounds or other body cavities while their internal spaces are maintained below atmospheric pressure.
The European patent application discloses a bottle having a neck with a cylindrical external surface and defining an outlet surrounded by a plane end face which, in turn, is surrounded by an undercut shoulder. A closure of elastomeric material has an end wall adjacent the end face of the neck and a cylindrical portion which surrounds the neck and has an internal shoulder engaging the undercut shoulder of the neck. The end wall of the closure is flat and is connected with one end of a conduit which can receive pus from a wound. In order to facilitate evacuation of air from the bottle, the internal surface of the cylindrical portion of the closure is configurated in such a way that it defines a passage for the escape of air from the bottle. The bottle is made of glass which creates the danger of implosion when the pressure within the bottle is below atmospheric pressure. Moreover, the making of a specially designed closure (which defines the aforementioned air evacuating passage or passages) contributes to the initial cost of the bottle-closure combination. Still further, the neck of the bottle must have a large outer diameter in the region of the outlet in order to establish an external shoulder which can be reliably engaged by the cylindrical portion of the closure.